Western blots analysis (Figures 10 and 11, and Supplementary Figures 1 and 2) revealed a significant increase in the protein levels of TMPRSS2 protease (which plays a crucial role in the processing of the SARS-CoV-2 proteins) in COPD subjects as compared to smokers and non-smokers. This evidence concerns the gene TMPRSS2 and chronic obstructive pulmonary disease.